CVE-2017-5637
Two four letter word commands "wchp/wchc" are CPU intensive and could cause spike of CPU utilization on Apache ZooKeeper server if abused, which leads to the server unable to serve legitimate client requests.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 73.1%, higher than 99% of all known CVEs. Patch or mitigate before the next change window.
Description
Two four letter word commands "wchp/wchc" are CPU intensive and could cause spike of CPU utilization on Apache ZooKeeper server if abused, which leads to the server unable to serve legitimate client requests. Apache ZooKeeper thru version 3.4.9 and 3.5.2 suffer from this issue, fixed in 3.4.10, 3.5.3, and later.
- CVSS 3.0
- 7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 73.06% probability · 99th percentile
- Public exploits
- 1 in Exploit-DB · first 2 July 2017
- CISA KEV
- Not listed
- Weakness
- CWE-306, CWE-400
- Affected
- apache/zookeeper · debian/debian linux
- Source
- security@apache.org
EPSS moved from 68.5% on 21 September 2026 to 73.1% on 27 October 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
Public exploits (1)
Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.
References
- http://www.debian.org/security/2017/dsa-3871Third Party Advisory
- http://www.securityfocus.com/bid/98814Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2017:2477
- https://access.redhat.com/errata/RHSA-2017:3354
- https://access.redhat.com/errata/RHSA-2017:3355
- https://issues.apache.org/jira/browse/ZOOKEEPER-2693Issue Tracking, Mitigation, Vendor Advisory
- https://lists.apache.org/thread.html/053d9ce4d579b02203db18545fee5e33f35f2932885459b74d1e4272%40%3Cissues.activemq.apache.org%3E
- https://lists.apache.org/thread.html/58170aeb7a681d462b7fa31cae81110cbb749d2dc83c5736a0bb8370%40%3Cdev.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/bcce5a9c532b386c68dab2f6b3ce8b0cc9b950ec551766e76391caa3%40%3Ccommits.nifi.apache.org%3E
- https://lists.apache.org/thread.html/rca37935d661f4689cb4119f1b3b224413b22be161b678e6e6ce0c69b%40%3Ccommits.nifi.apache.org%3E
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://www.oracle.com/security-alerts/cpujul2020.html
- http://www.debian.org/security/2017/dsa-3871Third Party Advisory
- http://www.securityfocus.com/bid/98814Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2017:2477
- https://access.redhat.com/errata/RHSA-2017:3354
- https://access.redhat.com/errata/RHSA-2017:3355
- https://issues.apache.org/jira/browse/ZOOKEEPER-2693Issue Tracking, Mitigation, Vendor Advisory
- https://lists.apache.org/thread.html/053d9ce4d579b02203db18545fee5e33f35f2932885459b74d1e4272%40%3Cissues.activemq.apache.org%3E
- https://lists.apache.org/thread.html/58170aeb7a681d462b7fa31cae81110cbb749d2dc83c5736a0bb8370%40%3Cdev.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/bcce5a9c532b386c68dab2f6b3ce8b0cc9b950ec551766e76391caa3%40%3Ccommits.nifi.apache.org%3E
- https://lists.apache.org/thread.html/rca37935d661f4689cb4119f1b3b224413b22be161b678e6e6ce0c69b%40%3Ccommits.nifi.apache.org%3E
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://www.oracle.com/security-alerts/cpujul2020.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.